With major stock market indexes coming off their first two-week winning streaks of the year, UBS' Art Cashin says this winter's frigid weather has helped traders overcome worries about emerging markets and an economic slowdown.

Concerns over the Fed's plans to scale down its economic stimulus programs, coupled with pullbacks in emerging markets, made for a weak start to 2014. Then came several sets of weaker-than-expected economic data. But as markets rallied, the winter storms plaguing the East Coast provided traders a convenient scapegoat for the bad numbers, Cashin said Tuesday, calling the nasty weather a "get-out-jail-free card."

"We got lousy payroll numbers and we had a rally that day," Cashin said on CNBC's "Squawk on the Street." "We've had pretty miserable numbers since and everybody's excusing it, including the Fed, that it may all be weather related."

Cashin added: "We have nothing but tainted data. Things have quieted down. The emerging markets did not spiral off a cliff, so more money is coming back in. We're getting near the old highs, and that's going to be a critical area."

The bands of resistance in the S&P 500 on Tuesday should remain between around 1,838 and 1,841, said Cashin, USB's director of floor operations at the NYSE. If the S&P breaks through those levels, it should hit fresh resistance between around 1,848 and 1,851, he said.

Cashin added that if the U.S. economy slows down, absent of weather effects, it will leave the Fed hard-pressed to find a solution.

"The Fed doesn't have many places to go. It's already at zero interest. They tried quantitative easing, and one of the reasons they're pulling out of QE is it's been thoroughly ineffective," Cashin said. "They feel they're pushing on a string, so they have a problem. ... [The market] can continue to wedge its way through, but at some point we're going to lose the weather as an excuse and then we're going to find out if the economy is really slowing down or not."

—By CNBC's Jeff Morganteen. Follow him on Twitter at @jmorganteen and get the latest stories from "Squawk on the Street."